Process for drawing a glass band from the surface of the molten glass metal



'Dec. 27, 1932. 1,892,459

PROCESS FOR DRAWING A GLASS BAND FROM THE SURFACE OF THE MOLTEN GLASS 1mm, v

B. ENGEL.

Filed Nov. 6. 1951 [NI/EH70}? BER/ HARD Ell/GELS face of t the width and thickness of Patented Dec. 27, 1932 UNITED STATES PATENT OFFICE EBOCESS FOB DRAWING A GLASS BAND FROM THE SURFACE OF THE MQLTEN GLASS METAL Application filed November 6,

The present invention relates to a mechanical production of flat-glass-plates by drawing a glass band from the free surface of the molten metal.

Until now this was done by keeping constant the distance between the bottom of the smelting at or drawing-cuvette and the sure metal, i. e. the position of the glass surface to the drawing-apparatus, by allowing a constant flow of fresh glass to pass in uniform quantity to the drawingcuvette. But this requires great quantities of glass to be ready for the actual manufacturmg process, and as these cannot be kept permanently in uniform temperature and condition, they are the cause of faults which afiect the quality of the product.

In order to prevent these unavoidable faults occurring through having to keep ready such great quantities of glass, trials have been made to draw glass molten in the p0t,.viz. especially refined glass, directly from the pot in which it was molten or out of special drawing-euvettes, putting up with the disadvantage of always having to begin anew a glass plate and of the unavoidable loss connected therewith.

But it was found that useful glass plates could not be made, because in consequence of the continual change of the distance between the glass surface and the drawing apparatus, even with drawing-apparatus, caused by the sinkin of the glass-surface in the drawing-vessefi the glass band drawn out always changed.

These drawbacks of the processes hitherto used are now done away with according to the present invention firstly b to add any glass to the filled pot or drawingvessel during the drawing-process, so that the glass band produced is formed only out of the contents of the pot or drawing-vessel, and further, by keeping the distance between the free surface of the composition in the pot or drawing-vessel and the actual drawing-apparatus, especially the pair of drawing-rollers of the drawing-apparatus which come into contact with the glass hand through reciprocal movement of the drawing-vessel the arrangement of a fixed l y not having 1981, Serial No. 573,491, and in Germany November 7, 1880.

and the drawing-apparatus, i. e. either by uniformly raising the drawing-vessel or by uniformly lowering the drawing apparatus, uniform during the whole drawing-process.

Figs. 1, 2 and 3 of the accompanying drawing are showing two forms 0 an apparatus for the process according to the present invention.

According to Figs. 1 and 2 a pot g filled with glass, is used for forming the glass band, the pot being closed from all sides and having no access. This pot g is arranged below the drawing-shaft a of a glass drawing-machine. The glass plate is lifted out in the known manner and conducted between the rollers d of the drawing-apparatus. The withdrawal of the glass late would of course lower the glass level in t e pot 9, whereby the height It would get smaller and the height w greater. But the alteration of the height w would afi'ect the drawing-process and the quality of the glass plate, for which reason, according to this invention, the distance to should always be kept constant during the drawing-process. This is obtained for instance by means of a lifting-apparatus 2' which raises the glass pot uniformly. Fig. 1 shows the pot in its initial position, and Fig. 2 shows it in its raised position. Fig. 2 also shows that the height to has remained the same as height w, while height It has become ess.

In form 3 (Fig. 3) the same effect is obtained by pot 9 remaining at rest, while the drawing-shaft z is lowered with uniform speed. In this case also height w remains constantwhile height It gets less.

I claim The hereinbefore described method of drawing glass in selected form from a bath of molten glass exhausted in the drawing, which comprises drawing the glass upwardly in the selected form by traction exerted thereon and maintaining constant the distance between the point of application of the traction and the surface of the bath by a relative movement between the traction means and the con tainer for the bath of glass.

BERNHARD ENGELS. 

